1. Field of the Invention
The present invention relates to a charged particle optical system which is used in an apparatus that uses a charged particle ray therein such as an electron beam, and a scribing apparatus using the same.
2. Description of the Related Art
An opt-electronic element for controlling the optical properties of an electron beam is used in an electron beam exposure apparatus. In the opt-electronic element, a deflector is an element which deflects an electron beam so as to make the electron beam scan a desired region and scribe an image on the region. WO 2010/125526 discloses an electrostatic deflector which simultaneously deflects a plurality of electron beams with an electric field. The deflector has a slim comb tooth structure in which two electrodes dovetail with each other while being separated by a gap, and deflects a beam row with an electric field which has been generated in the gap of the comb tooth structure.
In an electrostatic deflector which deflects the electron beam with the electric field, generally, deflection sensitivity changes according to a manufacture error of a gap between the electrodes, in which the electric field is generated. A change of the deflection sensitivity may reduce the uniformity of a scanning amplitude of the electron beam and the parallelism of the electron beam at the time of parallel scanning in combination with a lens. Particularly, when a plurality of electron beams is simultaneously deflected, if there is distribution (ununiformity) in the gaps between electrodes in the deflector, it becomes less easy to correct an individual deflection amount of the plurality of the electron beams. Accordingly, in order to uniformize the deflection amounts of the electron beams, it is important to reduce the distribution of the gaps between electrodes.